Can I make video game clips from any game like Minecraft ones?
People can make Minecraft videos in Blender by importing characters+rigging and worlds and then animate and render them. For example this question has images that shows some of the process:
Cubic character armature deform
It's not like people are making screen captures of a game they played, then importing that video and applying a different skin/texture to the characters, that's not how it works. It would be the same as if you recorded a bit of Starwars and expected there to be an easy way to redress all the storm troopers to look like indiana jones.

Currently there are no easy ways to replace garments on recorded footage, but that doesn't mean there aren't complicated ways.
The literature
Ways are emerging to help automate the process of match making and garment replacement, but they are early proof of concept, and are not likely to be included in Blender any time soon (or indeed possibly never)